Oar



IN VEN TOR.

v 04 ATTORNEYS.

Jan. 7, i930.

T. R. KEENAN OAR Fild Nov. 6, 192a" Patented Jan. 7, 1930 1 THOMAS R. KEENAN, 0F SAN FRANGISGO, CALIFORNIA OAR Application filed November 6, 1928.

This invention relates to boat oars, and especially to that type used in racing boats, where such qualities as rigidity, light Weight,

. and strength are essential requisites. ,5 Heretofore many attempts have been made to construct a light rigid oar for racing purposes, the general lines of attempt being that of first grooving the exterior surface of the loom, and second, grooving the interior to form a tubular loom. The first structure materially lightens the oar without reducing its strength but the grooves form a corrugated surface which collect dirt and it furthermore produces considerable resistance when rowing against wind and waves. The second structure reduces Weight, and in addltlon leaves a smooth exterior surface, but it requires a loom which is built up of several sections of wood grooved and glued together. Such a structure is costly, and there is a tendency towards warping the loom. p.

The object'of the present invention 1s to generally improve and simplify the construction and operation of oarsof the character described, to provide an oar in which the loom is of the tubular type so as to provide a smooth exterior surface, and further to provide an oar in which the loom consists of only two. sections which are grooved to form a cross 30 section of substantially I-beam shape and which will require only a single glued joint.

The oar is shown by way of illustration in the accompanying drawings, in which Fig. 1 is a plan View ofthe oar, said View being partiallybroken away and being shown aartially in section,

Fig. 2 is a side elevation or edge View of the oar, this view being also partially broken away and partially in section,

Fig. 3'is a diagrammatic View of the oar, Fig. 4 is a cross section of the loom taken on line IVIV of Fig. 1,

Fig. 5 is a similar view showing the two sections of the 100m separated,

Fig. 6 is a cross section of the blade taken on line VIVI of Fig. 1.

Referring to the drawings in detail, particularly Figs. 1, 4, 5 and 6, A indicates in gener- -al the blade of the oar, B the loom, C the button, D the cult connected therewith, and E Serial "No. 317,613.

the handle or inboardsection of the loom.

The loomconsists of two sections, generally indicatedat 2 and 3. The section2 is inte- .riorly grooved, as indicated at 4 and. 5, and theyare separated by a central web or cross piece 6. The loom sectionl3 is similarly grooved, as indicated at a and 5* and these grooves are separated by a central section or crosspiece 6. i The grooves may be formed in any suitable manner, and they extend from of properbalance. The two sections of the loom are glued together along the line indicatedat'T, see Fig. 4. Theloom is according ly made two halves or sections, which are secured together by means of a single glue joint, and it should furthermore be noted thatthls gluejoint is parallel to the lines of stress produced when the oaris in ac as will hereinafter be described. 1

When thetwosections ofthe loom, 2 and 3,

tual use,

are assembledand glued together, the cross ,pleces Stand G join each other and they thus form a central brace which extends from the 0111i." to the blade, thus materially strengtheningit', astheline of stress when the oar 1s lnuse 1s cross wise of the cross piece, orin, the direction of the dotted line indicated at VIXI X, see Fig. 4:. The sec- 13101118 6 and 6 form the web of theI-beam while the portion 2 forms one web and the section2 the other web of the beam.

The cheeks ofthe blade, indicated at 10, 10

may be formed integral with the loom seetions, or they may be glued thereto along the lines indicated at 11, the structure of the blade being merely a matter of choice.

In actual operation, referring to Fig. 3,

when an oar is being used, it is supported in an oar lock indicated by fulllines at 12. The

oarsmen grasp the handle section E, and pull The thereonin the directionof arrow 0;.

.blade A isat that time submerged just below-the surface of the water, and when a heavy pullis exerted on the handle theloom between the cuff and the blade tends to bend, asindicated by the dotted line 14:. The glue joint between the loom sections 2 and 3 is vertical with relation to the line of bending moment, and as such is subjected to a comparatively small amount of stress. The cross piece consisting of the sections 6 and 6* is disposed at right angles to the glue joint and bending moment or stress is thus exerted crosswise thereof. In this manner a rigid, light oar is obtained.

Oars have heretofore been made in which the loom is glued up of three sections. Two glue joints are required in such structures, and the glue joints are furthermore disposed at right angles to the line of bending moment. They will accordingly be placed in a position where they absorb the stress cross wise of the glue joint, or where a sheer action is produced. This is not desirable as the glue joint is comparatively weak when subjected to sheer, furthermore, by providing a structure which requires two glue joints which are arranged in this manner, it has been found that there is a tendency to warpthe loom, thus bringing the blade out of alignment with the loom. This is of course also objectionable.

By constructing the oar as here shown, the glue joint is merely subjected to a bending moment when the oar is under stress, this being the ideal method of applying stress to a glue joint. Furthermore, by disposing the glue joint parallel to the blade warping tendencies are reduced and alignment of the oar is maintained.

While certain features of the present invention are more or less specifically described, I wish it understood that various changes may be resorted to within the scope of the appended claims, similarly, that the materials and finishes of the several parts emloyed may be such as the manufacturer may decide, or varying conditions or uses may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent 1. An oar of the character described, comprising a loom and a blade, said loom being divided longitudinally into two halves which extend from the handle end of the loom to the tip of the blade, said halves presenting adjoining flat faces parallel with the face of the blade, and each flat" face having a pair of spaced grooves cut therein forming a central cross piece disposed at right angles to the flat face of the blade.

2. An oar of the character described comprising a loom and a blade, said loom being 7 divided longitudinally into two halves which extend from the handle end of the loom to the tip of the blade, said halves presenting adjoining fiat faces parallel with the face of the blade, each flat face having a pair of spaced grooves cut therein forming a central cross piece disposed at right angles to the flat face said channels and cross piece extending substantially from end to end of the loom and being disposed at right angles to the flat face of the blade on the oar and the glue joint being parallel to the flat face of the blade.

. THOMAS It. KEENAN. 

